Description: Changes in plant community traits along an environmental gradient are caused by interspecific and intraspecific trait variation. However, little is known about the role of interspecific and intraspecific trait variation in plant community responses to the restoration of a sandy grassland ecosystem. We measured five functional traits of 34 species along a restoration gradient of sandy grassland (mobile dune, semi-fixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China. We examined how community-level traits varied with habitat changes and soil gradients using both abundance-weighted and non-weighted averages of trait values. We quantified the relative contribution of inter- and intraspecific trait variation in specific leaf area (SLA), leaf dry matter content (LDMC), leaf carbon content (LCC), leaf nitrogen content (LNC), and plant height to the community response to habitat changes in the restoration of sandy grassland. We found that five weighted community-average traits varied significantly with habitat changes. Along the soil gradient in the restoration of sandy grassland, plant height, SLA, LDMC, and LCC increased, while LNC decreased. For all traits, there was a greater contribution of interspecific variation to community response in regard to habitat changes relative to that of intraspecific variation. The relative contribution of the interspecific variation effect of an abundance-weighted trait was greater than that of a non-weighted trait with regard to all traits except LDMC. A community-level trait response to habitat changes was due largely to species turnover. Though the intraspecific shift plays a small role in community trait response to habitat changes, it has an effect on plant coexistence and the maintenance of herbaceous plants in sandy grassland habitats. The context dependency of positive and negative covariation between inter- and intraspecific variation further suggests that both effects of inter- and intraspecific variation on a community trait should be considered when understanding a plant community response to environmental changes in sandy grassland ecosystems. Community trait responses to habitat changes were dominated by the interspecific trait variation. The intraspecific trait variation also played a role in changes of community-level traits. Both effects of inter- and intraspecific variation on community trait should be considered when understanding plant community response to environmental changes.

Description: Estimating transpiration of the trees in agroforestry system is important in water management of the site. Sap flow of intercropped fast growing young poplar trees and microclimate factors in semiarid northeastern China was measured in two growing seasons (2008 and 2009). Sapwood growth and water storage of wood and leaf increment during the growing season were involved in the calculation of sap flow. The results showed that diurnal variation of sap flow followed to that of short wave solar radiation. Sap flows both in 10 min mean and daily gross values mainly depended on solar radiation and vapor pressure deficit, and the relations well fit hyperbolic function. The regression coefficients of monthly window data indicated that the seasonal variation of sap flow capacities decreased gradually from June to September. Moderate soil water stress of upper soil layer (0–50 cm) did not constrain the sap flow because the trees could use the water at deeper soil layer. The daily sap flow per tree ranged 0.8 to 18.1 and 3.7 to 23.8 kg d -1 tree -1 , with averages of 8.7 and 14.3 kg d -1 tree -1 in 2008 and 2009 respectively. An empirical model was established to estimate the sap flow of the poplar trees by solar radiation, vapor pressure deficit, leaf area index and Julian days. Copyright © 2011 John Wiley & Sons, Ltd.

Description: [1]  Understanding the sources and fate of organic matter (OM) sequestered in continental margin sediments is of importance because the mode and efficiency of OM burial impacts the carbon cycle and the regulation of atmospheric CO 2 over long time scales. Shallow continental shelf seas such as the East China Sea are particularly active regions in terms of organic matter production and recycling. However, our limited understanding of controls on the spatial variability in sedimentary OM content and composition currently hinders the development of robust models that describe the quantity and type of organic matter that is ultimately buried within these heterogeneous, dynamic systems. We carried out molecular (lignin-derived phenols from CuO oxidation), elemental, isotopic (δ 13 C, Δ 14 C), and sedimentological (grain size and mineral surface area) analyses in order to examine spatial variability in the abundance, source, age and particle associations of OM presently accumulating in surface sediments of the East China Sea. Higher terrigenous organic matter values were found in the main accumulating areas of fluvial sediments, including the Changjiang (Yangtze) Estuary and Zhejiang-Fujian coastal zone. Isotopic and biomarker data suggest that the sedimentary OM in the inner shelf region was dominated by aged (Δ 14 C = -423 ± 42‰) but relatively lignin-rich OM (Λ = 0.94 ± 0.57 mg/100 mg OC) associated with fine-grained sediments, suggesting important contributions from soils. In contrast, samples from the outer shelf, while of similar age (Δ 14 C = -450 ± 99‰), are lignin-poor (Λ = 0.25 ± 0.14 mg/100 mg OC) and associated with coarse-grained material. Regional variation of lignin phenols and OM ages indicating that OM content is fundenmentally controlled by hydrodynamic sorting (especially, sediment redistribution and winnowing) and in situ primary production. Selective sorption of acid to aldehyde in clay fraction also modified the ratios of lignin phenols. The burial of lignin in East China Sea is estimated to be relatively efficient, possibly as a consequence of terrigenous organic matter recalcitrance and/or relatively high sedimentation rates in the Changjiang Estuary and the adjacent Zhejing-Fujian mud belt.

Description: Recent dramatic changes of freshwater systems in high latitudes will allow Submarine Fresh Groundwater Discharge (SFGD) to play a more important role in the coastal environment; especially in that SFGD will directly effect heat flux. Toyama Bay, along the central western Japan coast, is a suitable and representative case study area to estimate SFGD flux using hydrographic properties since multiple high-flow rate SFGD sites exist there. Salinities averaged over the water column (depth range 10–100 m) measured during research cruises in June 2003 and May 2005 show lower levels in the eastern than the western area in this bay. Together with monthly hydrographic properties over a 10-year period (1987-1998), the low salinity water mass in the eastern area exists consistently but distinctly and varies systematically, as does nutrient flux, affected by SFGD more than riverine input. SFGD fluxes in June 2003 (1 x 10 8 m 3 month -1 ) and May 2005 (〈1 x 10 8 m 3 month -1 ) were estimated using a box model, which is divided into a shallow box (0 – 40 m) and a deeper box (40 – 100 m). The monthly flux ratio between the SFGD and the river inputs is 13% in June, comparable to higher values reported in other global studies. Our results demonstrate that the box model analysis, based on hydrographic observations in coastal areas, is an efficient approach that can be used to estimate SFGD fluxes between the land and ocean.

Description: [1]  The time scale of transport processes in estuarine and coastal regions can be evaluated using natural radionuclides with different half-lives. The distribution patterns of 7 Be, 210 Pb and 234 Th in the water column from April to July 2008 were used to calculate the removal and residence times in the Changjiang Estuary. The results showed that the maximum particulate activities of 7 Be, 210 Pb and 234 Th were observed approximately 150 km downstream (the turbidity maximum zone) of the freshwater end-number. The mean distribution coefficients (K d , cm 3  g -1 ) of the high suspended particulate matter (SPM) group are higher than those of the lower SPM group for 7 Be and 210 Pb; for 234 Th, the reverse is true. Based on a material balance in two-dimensional models of 7 Be, 210 Pb and 234 Th in the Changjiang River mouth, the removal times of these nuclides were approximately 0.66-12, 1.6-21 and 1.2-5.4 d, respectively. The residence times increased toward the seaward side. In the coastal region, the removal times of 7 Be, 210 Pb, and 234 Th calculated by material balance in one-dimensional models were approximately 1.1-26, 1.2-27, and 0.70-23 d, respectively. Moreover, an enhanced resuspension process not only controlled the partitioning of 7 Be, 210 Pb, and 234 Th between the particulate and dissolved phases, but also this process may play a dominant role in controlling the dynamic behavior of SPM in the water column compared with the advection input/output fluxes of the SPM in the river mouth areas. The removal and the resuspension fluxes were comparable in the estuary. Meanwhile, old composition (which deposition into the seabed long time enough for the decay of 7 Be completely) occupied only a small part in the resuspended sediment during resuspension process.

Description: In case-control studies, exposure assessments are almost always error-prone. In the absence of a gold standard, two or more assessment approaches are often used to classify people with respect to exposure. Each imperfect assessment tool may lead to misclassification of exposure assignment; the exposure misclassification may be differential with respect to case status or not; and, the errors in exposure classification under the different approaches may be independent (conditional upon the true exposure status) or not. Although methods have been proposed to study diagnostic accuracy in the absence of a gold standard, these methods are infrequently used in case-control studies to correct exposure misclassification that is simultaneously differential and dependent. In this paper, we proposed a Bayesian method to estimate the measurement-error corrected exposure-disease association, accounting for both differential and dependent misclassification. The performance of the proposed method is investigated using simulations, which show that the proposed approach works well, as well as an application to a case-control study assessing the association between asbestos exposure and mesothelioma. Copyright © 2013 John Wiley & Sons, Ltd.

Description: BACKGROUND: More reliable clinical outcome prediction is required to better guide more personalized treatment for patients with primary glioblastoma multiforme (GBM). The objective of this study was to identify a microRNA expression signature to improve outcome prediction for patients with primary GBM. METHODS: A cohort of Chinese patients with primary GBM (n = 82) was analyzed using whole-genome microRNA expression profiling with patients divided into a training set and a testing set. Cox regression and risk-score analyses were used to develop a 5-microRNA signature using 41 training samples. The signature was validated in 41 other test samples, in an independent cohort of 35 patients with GBM, and in the Cancer Genome Atlas data set. RESULTS: Patients who had high risk scores according to the 5-microRNA signature had poor overall survival and progression-free survival compared with patients who had low risk scores. Multivariate Cox analysis indicated that the 5-microRNA signature was an independent prognostic biomarker after adjusting for other clinicopathologic and genetic factors, such as extent of resection, temozolomide chemotherapy, preoperative Karnofsky performance status score, isocitrate dehydrogenase 1 ( IDH1 ) mutation, and O-6-methylguanine-DNA methyltransferase ( MGMT ) promoter methylation status. CONCLUSIONS: The 5-microRNA signature was identified as an independent risk predictor that identified patients who had a high risk of unfavorable outcome, demonstrating its potential for personalizing cancer management. The authors concluded that this signature should be evaluated in further prospective studies. Cancer 2012. © 2012 American Cancer Society.

Description: Atmospheric deposition can deliver new nutrients to the surface water and support primary productivity. Here we report a phytoplankton bloom that developed in the Yellow Sea in the spring of 2007 3–4 days following a dust storm accompanied by precipitation. Our data indicate that atmospheric deposition dominated the supply of new nutrients to the surface water in the central Yellow Sea during the dust event. Dust-derived nitrogen (N) supply was sufficient to support the observed phytoplankton growth, while, dust-derived iron (Fe) supply far exceeded that required by the biota. Granger causality test results further supported that dust-derived nutrients deposition was the cause for the observed bloom with a lag of 3–5 days. Our results contribute to the growing database linking phytoplankton blooms to atmospheric deposition derived fertilization effects. Both dry and wet deposition contributed nutrients to the surface ocean during this event; however, the nutrient loading from dry deposition alone was not sufficient to satisfy the demand of the phytoplankton in this bloom event.

Description: Organic nitrogen (N) uptake by plants has been recognized as a significant component of terrestrial N cycle. Several studies indicated that plants have the ability to switch their preference between inorganic and organic forms of N in diverse environments; however, research on plant community response in organic nitrogen uptake to warming and grazing is scarce. Here, we demonstrated that organic N uptake by an alpine plant community decreased under warming with 13 C– 15 N-enriched glycine addition method. After 6 years of treatment, warming decreased plant organic N uptake by 37% as compared to control treatment. Under the condition of grazing, warming reduced plant organic N uptake by 44%. Grazing alone significantly increased organic N absorption by 15%, whereas under warming condition grazing did not affect organic N uptake by the Kobresia humilis community on Tibetan Plateau. Besides, soil NO 3 –N content explained more than 70% of the variability observed in glycine uptake, and C:N ratio in soil dissolved organic matter remarkably increased under warming treatment. These results suggested warming promoted soil microbial activity and dissolved organic N mineralization. Grazing stimulated organic N uptake by plants, which counteracted the effect of warming. We demonstrated that warming decreased plant organic N uptake by 37% as compared to control treatment. Under the condition of grazing, warming reduced plant organic N uptake by 44%. Grazing alone significantly increased organic N absorption by 15%.

Description: The Changjiang is the most important source of freshwater and dissolved organic matter (DOM) for the East China Sea. However, knowledge regarding the sources, seasonal fluxes and fluvial transport of terrigenous DOM (tDOM) in the Changjiang is lacking. To fill this knowledge gap, we measured dissolved organic carbon (DOC) and dissolved lignin in water samples collected in the middle and lower Changjiang under different hydrological conditions. Additional samples were collected bi-weekly in the lower Changjiang. Through comparisons with other rivers, we found that the DOC in the Changjiang is mainly from soil organic matter and has a higher fraction of tDOM during flood. Mass balance model results indicate that approximately 33% of the dissolved lignin discharged into the middle and lower Changjiang is removed during its transport to the lower reach during both low discharge and flood periods. Based on a comparison of the removal rates under these two contrasting hydrological conditions and considering the lower organic carbon content and fine grain size of the Changjiang's suspended particles, we speculate that the major process for the removal of dissolved lignin is sorption, and potentially flocculation by suspended particles. Changjiang discharges 1.4 ± 0.10 Tg yr -1 and 8.6 ± 0.30 Gg yr -1 DOC and dissolved lignin to the estuary during the period of July 2010 to June 2011, respectively. Seasonal distributions of DOC and dissolved lignin fluxes are controlled by water discharge, which will be affected by future climate change and the Three Gorges Dam (TGD).